A door, a lid, or the like for closing an opening is provided on a vehicle opening such as an entrance/exit or a trunk room of an automobile, and a weather strip for sealing a gap between the opening and the door, the lid, or the like is installed on the periphery of the opening. In addition, a flange that reinforces the opening is provided on the periphery of the vehicle opening. The weather strip is a long member made of a polymer material through extrusion molding and includes a seal portion having a hollow cylindrical shape and a holding portion. The holding portion is configured to include a bottom wall and a first lateral wall and a second lateral wall which stand from both ends of the bottom wall and has a substantially U-shaped cross section. The seal portion is provided on an outer surface of the first lateral wall, which is located at a vehicle exterior side in a state in which the weather strip is installed on the flange, and holding lips that hold the flange at the periphery of the vehicle opening are provided on the inner surfaces of the first lateral wall and the second lateral wall.
The weather strip is installed due to the holding lips of the holding portion holding the flange, and the seal portion comes into contact with the door, the lid, or the like such that the gap between the vehicle opening and the door, the lid, or the like is sealed. In addition, in order to cover and hide the flange, a product having only the holding portion without the seal portion is installed on the flange, in some cases.
Here, a thickness of the flange is different depending on a region of the opening. The flange is made of one metal plate at a thin region, but is configured to be made of three or more metal plates, which overlap each other and are subjected to spot welding, at a thick region. In related art, the holding portion of the weather strip is formed to have a constant opening width corresponding to the thickness of the thinnest region of the flange. In other words, an angle between the bottom wall and the first lateral wall and an angle between the bottom wall and the second lateral wall of the holding portion are constant throughout in the longitudinal direction. In such case, since a load required for inserting the flange into the holding portion increases in a region in which the flange has a large thickness, it is difficult to install the weather strip on the flange. Therefore, JP-A-2000-33840, JP-A-H02-175128, and JP-A-H05-147098 disclose inventions in which an opening width of a holding portion that is installed on a flange is partially varied depending on a thickness of the flange, specifically, inventions in which an angle between a bottom wall and a lateral wall on the vehicle interior side is partially varied in a longitudinal direction in a state in which a weather strip is installed on the flange.
In JP-A-2000-33840, using a dedicated molding apparatus having an accommodating groove at the center, the opening width of the holding portion is varied corresponding to the thickness of the flange by causing the angle between a second lateral wall (lateral wall on the vehicle interior side) and the bottom wall of the weather strip after extrusion molding to be partially varied in the longitudinal direction. Specifically, by setting a part of the weather strip, whose holding portion is formed to have a constant opening width corresponding to the thickness of the thinnest region of the flange, in an accommodating groove of the molding apparatus, and then driving a wedge-shaped jig into a space between the first lateral wall and the second lateral wall, the second lateral wall is expanded outward. In this manner, a weather strip having a wide portion in a part of the holding portion is obtained.
In JP-A-H02-175128, first, a preform of a weather strip, which is extruded (pre-formed) from an extruder such that angles of a first lateral wall and a second lateral wall with respect to a bottom wall is larger than a maximum angle of a finally completed product, is passed between a pair of rollers having a constant interval. In this manner, the first lateral wall and the second lateral wall are each pressed at a predetermined constant angle by the rollers from the outer side, and thereby a weather strip in which an opening width of the holding portion corresponds to the thickest region of the flange is obtained. Subsequently, the weather strip is further passed between a pair of rollers including a movable roller having a rotary shaft that can be displaced inward and outward in a width direction thereof and a fixed roller having a rotary shaft that is not displaced at a predetermined position. Thereby, the opening width of the holding portion is partially varied in the longitudinal direction corresponding to the thickness of the flange. Specifically, in a region corresponding to a region in which the flange has a small thickness, the movable roller is further displaced inward so as to further press the second lateral wall inward, and thereby an acute angle is formed between the second lateral wall and the bottom wall.
Also in JP-A-H05-147098, a preform of a weather strip is passed between a pair of rollers including a movable roller having a rotary shaft that can be displaced inward and outward in a width direction thereof and a fixed roller having a rotary shaft that is not displaced at a predetermined position and, similar to JP-A-2-175128, the movable roller is displaced inward and outward corresponding to a thickness of a flange. In this manner, an angle formed between the second lateral wall and the bottom wall is partially varied in a longitudinal direction thereof.